1. Field of the Invention
The present invention is directed to a system and method for protecting the identity of target telephone numbers being monitored by law enforcement agencies from unauthorized access.
2. Description of the Related Art
When law enforcement agencies monitor telephone calls to obtain evidence for use in criminal investigations, it is important to protect the identity of telephone numbers being monitored, known as target telephone numbers, from unauthorized access.
In order to monitor and/or record these telephone calls, it is necessary to route the telephone calls to a monitoring system, such as a Comverse InfoSys system, e.g., an Ultra monitoring system manufactured by Comverse InfoSys of Woodbury, N.Y., where such monitoring and/or recording can take place. That requires that network elements such as switches or SCPs (i.e., service control points) identify the target telephone numbers prior to routing the calls from these target telephone numbers to the monitoring system and subsequently to their destination. Because the network elements typically handle and route thousands of calling telephone numbers to receiving telephone numbers, identifying the target telephone numbers can be challenging.
In a conventional telephone call monitoring system, a calling telephone number would dial into a network. The network then routes the calling telephone number to the receiving telephone number. Commercial software packages are currently available in the market allowing the network operators to specify predetermined numbers in the network switches, such that calls made by or to these numbers will be routed to the law enforcement agency monitoring system.
However, often times, unauthorized users may gain access to these predetermined numbers stored on the network switches and thus learn which telephone numbers are being monitored (known as xe2x80x9ctargetsxe2x80x9d) by law enforcement agencies. Conventional methods allow switch maintenance personnel to provision and view these predetermined numbers on the network switches. In addition, switch maintenance and operation personnel may gain access to the Call Detail Records (CDR) generated by network switches, and learn from them about calls that have been specially redirected to the law enforcement monitoring system. Such access by unauthorized users jeopardizes the effectiveness of any telephone call monitoring and/or recording by law enforcement agencies. It is desired to prevent unauthorized users to access the identity of the target telephone numbers.
The present system and method prevents unauthorized access of target telephone numbers that a law enforcement agency wishes to monitor by encoding the target telephone numbers using a one-way encoding algorithm, prior to storing these target numbers in the network elements.
The present invention has been made to overcome the above-mentioned problems of the related art, and accordingly, the present invention provides a system and method to protect a target telephone number from unauthorized access, including a first one-way encoding unit encoding a target telephone number using non-reversible encoding; a storage unit storing the encoded target telephone number; a second one-way encoding unit encoding a calling telephone number and a receiving telephone number using the non-reversible encoding; a monitoring unit; and a comparing unit determining whether the stored encoded target telephone number matches the encoded calling telephone number and/or the receiving telephone number and routing a call between the calling telephone number and the receiving telephone number matching the target telephone number to the monitoring unit, wherein the monitoring unit monitors and/or records the call and connects the calling telephone number to the receiving telephone number.
The present invention further provides a system and method including a first one-way encoding unit encoding the target telephone number using non-reversible encoding; a storage unit storing the encoded target telephone number; a second one-way encoding unit encoding a calling telephone number and a receiving telephone number using the non-reversible encoding; a monitoring unit; and a comparing unit comparing the stored encoded target telephone number with the encoded calling telephone number and the receiving telephone number, determining therefrom whether the stored encoded target telephone number matches the encoded calling telephone number and/or the encoded receiving telephone number, routing a real target call between the calling telephone number and the receiving telephone number matching the target telephone number to the monitoring unit, and routing a false target call between the calling telephone number and the receiving telephone number not matching the target telephone number to the monitoring unit, wherein the monitoring unit filters the false target call from the real target call and monitors and/or records the real target call.
These together with other objects and advantages, which will be subsequently apparent, reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.